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Kolmanovsksiĭ IV 《Zhurnal obshche? biologii》2002,63(4):292-298
Functional reasons for specific changes in mammal foot skeleton occurring in course of formation and progressive evolution of locomotion on the parasagittal extremities are formulated for the first time. The paper establishes the base of the study of highly parasagittal forms (terrestrial catarhine monkeys, man and his ancestors), that evolved in primate history much later then their counterparts in other orders. The foot of primitive primate (Lemur catta) is scrutinized as a model of a primitive foot structure, that determined the peculiarities of foot evolution in higher forms. Primate foot traits as elements of general mammal foot evolution are described. Some specializations of the primate foot to the arboreal habitats are concluded to preclude the primate foot from progressing to the state inherent in highly advanced parasagittal members of other mammalian orders. 相似文献
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C F George 《BMJ (Clinical research ed.)》1983,286(6377):1533-1534
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N.I. Vavilov's theory of the centres of origin of cultivated plants is still as a methodological base for studying processes of domestication. This theory, along with archaeological, botanical, and molecular genetic data, helped to determine the most probable regions where the principal cultivated species were introduced into culture. The search for the mechanisms of origins of morphological changes in the course of domestication is one of evolutionary biology's oldest problems. Employing novd molecular biological data for solving this problem provides a key to the understanding of these mechanisms and helps to reconstruct a possible scenario of how the traits that distinguish domesticated plants from their wild relatives got involved into selection. It is hypothesized that distinct physiological and morphological differences important to ancient agrarians originated from quantitative and/or qualitative changes in the loci regulating the programmes of plant ontogeny. This hypothesis helps to reveal the mechanisms of origin of certain traits in the course of domestication, to study the connection between the direction of selection and how such traits are genetically controlled, and to outline particular ways for further detailed studies of the evolutionary aspect of domestication processes. 相似文献
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Thermoregulatory reactions of lactating cows (33 Kg milk/day) have been measured in summer (Tg 25° – 39°C) and in winter (Tg 9, 5° – 24°C) at 3-hr intervals, during four 24-hr cycles. The animals maintained an almost continuous peripheral vasodilation throughout the experimental period. The upper ambient temperatures at which a dairy cow maintains homoeothermy were calculated for different metabolic rates. At the maintenance level a dry cow may maintain homoeothermy at up to 24°C without sweating and up to 40°C if sweating at 50% of the maximal sweating capacity. For a cow producing 30 kg milk/day, the respective figures were 12°C and 24°C respectively. These data indicate that the thermoregulatory capacity of the animals in the natural climate considerably expands the thermal comfort temperature range.
Zusammenfassung Die wärmeregulatorischen Reaktionen milchgebender Kühe (33 kg Milch/Tag) wurden im Sommer (Tg 25° – 39°C) und im Winter (Tg 9, 5° – 24°C) in 3-Stunden Intervallen während 4 mal 24 Stunden periodisch gemessen. Die Tiere hatten eine beinahe kontinuierliche periphere Gefässerweiterung während der Versuchsperioden. Die obere Umgebungstemperatur, bei der Milchkühe homoiothermisch bleiben, wurde aus verschiedenen Stoffwechselraten berechnet. Auf dem Erhaltungsniveau kann eine trocken stehende Kuh die Homoiothermie bis 24°C ohne Schwitzen halten und bis auf 40°C bei Schwitzen bis 50% des maximalen Schwitzvermögens. Für eine Kuh, die 30 kg Milch/Tag leistet sind die entsprechenden Werte 12°C beziehungsweise 24°C. Diese Werte zeigen, dass das Wärmeregulationsvermögen der Tiere im natürlichen Klima den Wärmekomfort-Temperaturbereich erheblich ausdehnt.
Resume On a mesuré l'aptitude de thermorégulation de vaches en lactation (33 kg de lait par jour) toutes les 3 heures durant 4 cycles de 24 heures et cela aussi bien en été (Tg 25° à 39°C) qu'en hiver (Tg 9, 5° à 24°C). Les animaux ont présenté une vasodilatation périphérique assez constante durant toute la période des essais. On a en outre calculé, en partant de différents taux de métabolisme, la température ambiante maximum pour laquelle une vache laitière peut maintenir son homéothermie. Pour une vache sèche, ce maximum est de 24°C sans transpirer et de 40°C si elle transpire le 50% de sa capacité maximum. Pour une vache donnant 30 kg de lait par jour, ces chiffres s'abaissent à 12°C dans le premier cas, à 24°C dans le second. Ces chiffres montrent que la capacité de thermorégulation du bétail bovin augmente considérablement l'amplitude de la zone de confort thermique en climat naturel.相似文献
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The variational approach of evaluation for knowledge-based potentials is considered for the first time. In this approach, the problem to derive knowledge-based potentials is solved as the optimization task in the multiparametric model of atom types, reference states and interaction cutoff radii. Using analogy to liquid state theory we offered four new reference states and derived corresponding knowledge-based potentials. The cutoff radii and atom types are optimized to minimize averaged root-mean square deviations (RMSD) of the ligand docked positions regarding to the experimentally determined poses. The number of atom types is varied on the developed atom type tree with 6 root (C, N, O, S, P and the halogen type) and 49 apical atom types. We showed a pronounced effect of atom type choice on docking accuracy and proved that splitting of elements C, N and O of the periodic system up to the 18 optimal atom types essentially improves docking accuracy. 相似文献
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Since the 1980s, a new area of research entitled HRI (Human-Robot Interaction) has been emerging in the field of robotic studies. It focuses on the empirical study of the relationship between robots and human beings. This article aims to contrast the findings of roboticists concerning the interaction between humans and robots with anthropological studies which focus on the ritual interaction between gods and humans in specific religious contexts. This idea may seem provocative, but it is argued here that such a comparison can yield valuable insights both at a theoretical level and at an empirical one. This will be demonstrated with reference to ritual interactions between humans and gods in the Western Himalayas.
Depuis les années 1980, un nouveau domaine d'étude appelé HRI (Human-Robot Interaction) est apparu dans la recherche en robotique. Il s'agit d'une étude empirique des relations entre robots et êtres humains. Le présent article met en regard les observations de roboticiens sur les interactions entre humains et robots et les études anthropologiques consacrées à l'interaction entre dieux et humains dans des contextes religieux spécifiques. Pour provocatrice qu'elle puisse paraître, cette comparaison peut constituer une approche intéressante, du point de vue théorique aussi bien qu'empirique. L'auteur le démontre en référence à des interactions rituelles entre hommes et dieux dans les massifs occidentaux de l'Himalaya. 相似文献
Résumé
Depuis les années 1980, un nouveau domaine d'étude appelé HRI (Human-Robot Interaction) est apparu dans la recherche en robotique. Il s'agit d'une étude empirique des relations entre robots et êtres humains. Le présent article met en regard les observations de roboticiens sur les interactions entre humains et robots et les études anthropologiques consacrées à l'interaction entre dieux et humains dans des contextes religieux spécifiques. Pour provocatrice qu'elle puisse paraître, cette comparaison peut constituer une approche intéressante, du point de vue théorique aussi bien qu'empirique. L'auteur le démontre en référence à des interactions rituelles entre hommes et dieux dans les massifs occidentaux de l'Himalaya. 相似文献
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Kirchengast S 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》2007,65(2):181-191
At both extremes of reproductive phase female pregnancy outcome is described as poor. Beside a high rate of anovulatory cycles, pregnancies at these phases of the reproductive span are considered as risky for obstetric complications, and increased maternal and newborn morbidity and mortality. In the present study the associations between the age as well as somatic characteristics such as prepregnancy weight, stature, pelvic dimensions and pregnancy weight gain of 10765 women ageing between 12 and 49 years and newborn body dimensions and the mode of delivery as well as uterine child presentation were analysed. With increasing maternal age, maternal and newborn body dimensions increased significantly. Furthermore, extremely young mothers showed the lowest rates of caesarean sections, while mothers older than 40 years experienced the significantly highest rate of caesarean sections. Regarding newborn weight status, for mothers older than 35 years the highest rate of low weight newborns (< 2500 g) and the highest rate of macrosome newborns (> 4000 g) were found. Special risks were found in mothers older than 35 years, so the lower rates of ovulatory cycles during this phase of life may be interpreted as an adaptation to increased risks for complications and poor pregnancy outcome. 相似文献
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Hardie DG 《Current biology : CB》2000,10(20):R757-R759
The phenomenon whereby the presence of oxygen regulates the rate of glucose metabolism was first described by Louis Pasteur. A novel mechanism has now been discovered, involving the AMP-activated protein kinase cascade, that can account for the Pasteur effect in ischaemic heart muscle. 相似文献
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Karl J. Niklas 《American journal of botany》1994,81(10):1235-1242
Interspecific correlations between plant height and basal stem diameter (the allometry of height) and between stem length distal to where diameter is measured (the allometry of stem taper) were determined for a total of 265 species with self-supporting stems and for the shoots of five conifers and 15 angiosperm vine species. The allometric equations obtained for these data are proposed as a method to predict the heights of fossil plants for which basal stem diameters are either known or inferred, and to predict the missing lengths of fragmented stems based on the most proximal stem diameters observed. 相似文献
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F. Facchini 《Human Evolution》1991,6(5-6):461-469
The roots of ethics are to be found within man's freedom and his ability to pursue values from the choices he makes.
These values may be sought within the structure of the human being. Some of these values will correspond to man's vital needs
(such as socializing, cooperation, family ties, etc.), yet they are not to be interpreted as being genetically determined,
since they are consciously interiorized and experienced and planned at both individual and group level. Other values, such
as religion, a moral sense, or art transcend those needs strictly linked with physical life. These values may be considered
to be “natural universals” or ‘trans-cultural” values because they are to be found in various cultures. The fact that they
offer man an advantage, does not necessarily mean that they are genetically determined or that they have been fixed through
selection processes.
These can be extended to include the values that have matured from the historical experience of single human beings and groups.
The transcendental value of the person-man as opposed to infra-human beings, has also been confirmed as a priority criterion
for value judgements and for a rational ethics, particularly within the field of bio-ethics. 相似文献
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The fact that the growth of every organism, as it develops through cell multiplication from the ovum, eventually ceases, makes
plausible the hypothesis that each cell of an organism exerts some kind of inhibitory influence upon the growth and multiplication
of every other cell through the medium of some factorj. Each cell, however, is considered to possess an amount of a “growth factor”g, the activity of which is inhibited byj. In the course of development, most cells differentiate. A number of them remains relatively undifferentiated, and those
are used for repairs of natural tear and wear as well as for healing of wounds. With age either the number of those cells
or their “potency” decreases, which accounts for a general decrease in the speed of wound healing. Due to statistical fluctuations,
the amount of theg is not uniformly distributed amongst the cells. Some of them have accidentally a greater amount than others. As the number
or potency of the undifferentiated cells decreases with age, so does their inhibitory influence upon other cells. Therefore,
those cells which do have an accidental dental excess ofg-factor will begin to grow and multiply, producing neoplasms. Putting the above assumptions into mathematical form, it is
possible to derive a relation which gives theprobability of cancer incidence as a function of age. The theoretical relation is compared to the rather inadequate empirical data and
found in agreement with them. A relation for the speed of wound healing as a function of age is also derived, and also found
in general agreement with the rather scant data. Several other conclusions are discussed and possibilities of their practical
applications pointed out. 相似文献
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Spoljar-Vrzina SM 《Collegium antropologicum》2000,24(2):565-578
This article presents the most important results of an applied anthropological long-term study of the prolonged exile and return that many families are currently undergoing in Croatia. The results are elaborated with a special reflection upon two important overlapping issues concerning the methodological approach that was applied: firstly, it discusses the crucial questions which motivated the search for a tool that will not distort the experiences, reality and suffering of exile families; and secondly, it critically describes the application of the genogram (a tool borrowed from systemic family therapy) in the exile setting. This tool was not only useful in the clinical sense of psychotherapeutically helping the families, but was also a very flexible part of the methodology orientated towards evoking family history and providing valid knowledge about different family and living circumstances. 相似文献
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Hemingway J 《Parassitologia》1999,41(1-3):315-318
The application of biochemical and molecular biological techniques to the study of insecticide resistance has revolutionized our understanding of the underlying genetic basis of resistance. Using the examples of glutathione S-transferase and esterase-based metabolic insecticide resistance, three different routes via which increased insecticide detoxication can be achieved are elucidated. An understanding of these molecular pathways opens up new avenues for manipulating mosquito populations to restore insecticide susceptibility to the vectors. 相似文献
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